Peripheral arterial disease (PAD) is a leading cause of morbidity in older Americans due to disabling claudication leg pain during exercise. Claudication reduces functional independence by placing limitations on performing activities of daily living as well as employment possibilities. Claudication accounts for approximately 17% (4 million) of all Americans who have physical activity limitations (23 million). It is estimated that the 1994 national health care cost will exceed $3.3 billion from surgical procedures alone. We propose that an aggressive risk factor modification (ARFM) program, which includes exercise rehabilitation and dietary modification, will be an effective clinical strategy for the treatment of claudication pain with relatively low expense. The central hypothesis is that an ARFM program will enhance functional independence and quality of life in older claudicants by promoting muscular adaptations which improve peripheral blood flow, exercise capacity, and metabolic function. These beneficial changes will reduce claudication and symptomatology and risk factors for cardiovascular complications. Seventy PAD patients with claudication will be randomly assigned into either a 9-month ARFM program (N=35) or a usual care control group (N=35). The exercise rehabilitation portion of the ARFM program will consist of supervised intermittent walking, performed 3 times per week over 9 months at an initial intensity of 40% of maximum which will increase to 70% by the end of the program. Total time of walking per session will increase from 10 to 50 minutes during the program. The dietary modification portion of the ARFM program will consist of a one-hour weekly class which will educate patients about healthy eating habits based on the National Cholesterol Education Program guidelines. Free-living daily physical activity, claudication pain during treadmill tests, peripheral and central hemodynamic variables, muscle structure and function, and body composition will be assessed before and after the 9-month study. The significance of this clinical trial is that it will demonstrate that older claudicants can improve functional independence and reduce future morbidity by favorably altering cardiovascular disease and metabolic risk factors through an ARFM program.